As various energy resources become rarer, such as, for example, water resources, the public has become far more conscious of the need for energy savings, as well as the need for environmental protection. Thus, water saving products have been widely accepted in various areas. As an example, water saving aerator devices are now used far more frequently in the daily life of the public than has previously been the case. On the other hand, however, the present state of the art can only realize water savings by limiting the water flow rate, but has not been fully able to maintain stable flow rates under changing water pressures, and thus their water saving efficiency has not been fully satisfactory.
It has been known to employ flow compensators in devices such as kitchen aerators. For example, the assignee of the present application is also the assignee of U.S. Pat. No. 7,252,248 (“the '248 patent”), the entire disclosure of which is incorporated herein by reference thereto. This patent discloses a faucet aerator which incorporates a flow compensator to permit higher flow rates of water at lower water pressures flowing through the aerator itself. The flow compensator shown in the '248 patent is mounted in the flow path of the water through the aeration device and includes a plurality of spaced-apart water openings for the flow of water therein.
Other liquid control devices are known in the art such as that of U.S. Pat. No. 6,065,498. This patent includes a flow control device which provides variable resistance to liquid flow through a flow passage. In this device, however, a vortex flow path is used within a generator as the liquid flows into a housing so that as the inlet pressure increases the flow of water decreases therein.
In addition, in co-pending International Application No. PCT/US2010/041551, the disclosure of which is incorporated herein by reference thereto, a pressure compensator for stabilizing a flow of water is described which includes a rubber body, water compensating channels around the periphery of the body, and flow orifices through the body for controlling the flow rate of the water at various water pressures therein.
The search, however, has continued for improved small size pressure compensators for use in flow controllers, such as aerators of various types. Furthermore, the search has also continued for improved flow controllers which can demonstrate constant flow rates at a variety of different overall flow rates.